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    <meta http-equiv="content-type" content="text/html; charset=UTF-8"><title>CheckDatabaseNull</title></head>
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<font face="Verdana, sans-serif" size="2"><p align="center"><b><font size="4">CheckDatabaseNull()</font></b></p>
<p><b>语法</b></p><blockquote>

Text$ = <font color="#3A3966"><b>CheckDatabaseNull</b></font>(#Database, Column)</blockquote>

</blockquote>
<b>概要</b><br><blockquote>

检查指定的数据库列的内容是否为空。此命令只有在<a href="firstdatabaserow.html">FirstDatabaseRow()</a>、 <a href="previousdatabaserow.html">PreviousDatabaseRow()</a>或<a href="nextdatabaserow.html">NextDatabaseRow()</a>等函数调用成功后才有效。 

</blockquote><p><b>参数</b></p><blockquote>
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<table width="90%" class="parameters">
<tr><td width="10%"><i>#Database</i></td>
<td width="90%"> 
要使用的数据库。 

</td></tr>
<tr><td><i>Column</i></td>
<td> 
要使用的列。<a href="databasecolumnindex.html">DatabaseColumnIndex()</a> is available to get the index of a named column. 

</td></tr>
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</blockquote><p><b>返回值</b></p><blockquote>



Returns <font color="#924B72">#True</font> is the data is null, <font color="#924B72">#False</font> otherwise. 

 

</blockquote><p><b>备注</b></p><blockquote>

若要确定列的类型，可以使用<a href="databasecolumntype.html">DatabaseColumnType()</a> 。<br><br>注意︰ 每列此函数可以是只调用一次。因此如果需要超过一次使用此值，数据必须存储在变量中，因为所有的后续调用将返回错误值。This is an ODBC limitation. 

</blockquote><p><b>参阅</b></p><blockquote>

<a href="getdatabaseblob.html">GetDatabaseBlob()</a>, 
<a href="getdatabasedouble.html">GetDatabaseDouble()</a>, 
<a href="getdatabasefloat.html">GetDatabaseFloat()</a>, 
<a href="getdatabaselong.html">GetDatabaseLong()</a>, 
<a href="getdatabasequad.html">GetDatabaseQuad()</a> 

</Blockquote><p><b>已支持操作系统 </b><Blockquote>所有</Blockquote></p><center>&lt;- <a href=affecteddatabaserows.html>AffectedDatabaseRows()</a> - <a href="index.html">Database Index</a> - <a href="closedatabase.html">CloseDatabase()</a> -&gt;<br><br>

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